@localhost ffmpeg]# ./ffmpeg -i "../Planet Earth.mpg" -s 320x240 -aspect 4:3 -acodec aac -r 30 -bt 768 -vcodec h264 OUTPUT.mp4
FFmpeg version SVN-r9047, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-x264 --enable-pthreads --enable-libfaac --enable-libfaad --enable-encoder=x264
  libavutil version: 49.4.0
  libavcodec version: 51.40.4
  libavformat version: 51.12.1
  built on May 17 2007 10:04:43, gcc: 4.1.1 20060525 (Red Hat 4.1.1-1)
Input #0, mpeg, from '../Planet Earth.mpg':
  Duration: 01:02:00.7, start: 0.486089, bitrate: 4771 kb/s
  Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576, 15000 kb/s, 25.00 fps(r)
  Stream #0.1[0x1c0]: Audio: mp2, 48000 Hz, stereo, 256 kb/s
File 'OUTPUT.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'OUTPUT.mp4':
  Stream #0.0: Video: h264, yuv420p, 320x240, q=2-31, 200 kb/s, 30.00 fps(c)
  Stream #0.1: Audio: aac, 48000 Hz, stereo, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
x264 [error]: invalid width x height (0x320)
Error while opening codec for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height